diff --git a/packages/backend/src/controller/PKCECheck.ts b/packages/backend/src/controller/PKCECheck.ts
index 8fc5671..6fd4ee7 100644
--- a/packages/backend/src/controller/PKCECheck.ts
+++ b/packages/backend/src/controller/PKCECheck.ts
@@ -2,138 +2,94 @@ import type { SDK } from "caido:plugin";
 import { Body, RequestSpec, type Request } from "caido:utils";
 
 export class PKCECheck {
+  // 필요한 PKCE 파라미터 목록
+  private readonly requiredPKCEKeys = ["client_id", "response_type", "code_challenge", "code_challenge_method"];
+
+  // PKCE 취약점 테스트 메인 함수
   async test(sdk: SDK, req: Request): Promise<boolean> {
     const method = req.getMethod();
+    const url = req.getUrl();
+
+    // GET 요청이 아니면 검사하지 않음
     if (method !== "GET") {
       sdk.console.log("[PKCEDowngradeCheck] Not a GET request. Skipping.");
       return false;
     }
 
-    const query = req.getQuery();
-    const searchParams = new URLSearchParams(query);
-    const requiredKeys = ["client_id", "response_type", "code_challenge", "code_challenge_method"];
+    const searchParams = new URLSearchParams(req.getQuery());
 
-    if (!requiredKeys.every((key) => searchParams.has(key))) {
+    // 필수 PKCE 파라미터들이 모두 있는지 확인
+    if (!this.requiredPKCEKeys.every(key => searchParams.has(key))) {
       sdk.console.log("[PKCEDowngradeCheck] Required PKCE parameters missing. Skipping.");
       return false;
     }
 
-    const url = req.getUrl();
+    // OpenID 여부 확인
     const isOpenID = searchParams.get("scope")?.includes("openid") || url.includes("id_token");
     const methodVal = searchParams.get("code_challenge_method");
     const challengeVal = searchParams.get("code_challenge");
 
+    // 파라미터가 없으면 경고 리포트 생성
     if (!methodVal || !challengeVal) {
-      sdk.console.log("[PKCEDowngradeCheck] code_challenge or method missing. Skipping.");
-      await sdk.findings.create({
-        title: isOpenID
-          ? "[WARN] OpenID Flow PKCE Parameters Missing"
-          : "[WARN] OAuth2 Flow PKCE Parameters Missing",
-        description: `PKCE parameters are missing or incomplete for ${url}. This may indicate a misconfiguration.`,
-        request: req,
-        reporter: "PKCE Checker",
-      });
+      await this.reportFinding(sdk, req, url, isOpenID, "[WARN] PKCE Parameters Missing", "PKCE parameters are missing or incomplete.");
       return false;
     }
 
+    // code_challenge_method가 'plain'이면 취약할 수 있음
     if (methodVal === "plain") {
-      sdk.console.log("[PKCEDowngradeCheck] code_challenge_method is 'plain'. Skipping.");
-      await sdk.findings.create({
-        title: isOpenID
-          ? "[WARN] OpenID Flow PKCE Method is 'plain'"
-          : "[WARN] OAuth2 Flow PKCE Method is 'plain'",
-        description: `PKCE method is set to 'plain' for ${url}. This may indicate a downgrade vulnerability.`,
-        request: req,
-        reporter: "PKCE Checker",
-      });
+      await this.reportFinding(sdk, req, url, isOpenID, "[WARN] PKCE Method is 'plain'", "PKCE method is set to 'plain'. This may indicate a downgrade vulnerability.");
       return false;
     }
 
-    // Remove PKCE parameters to simulate a downgraded request
+    // PKCE 관련 파라미터 제거하여 다운그레이드된 URL 생성
     searchParams.delete("code_challenge");
     searchParams.delete("code_challenge_method");
     const downgradedQuery = searchParams.toString();
-    const scheme = req.getUrl().startsWith("https") ? "https" : "http";
+    const scheme = url.startsWith("https") ? "https" : "http";
     const downgradedUrl = `${scheme}://${req.getHost()}:${req.getPort()}${req.getPath()}?${downgradedQuery}`;
 
-    sdk.console.log(`${req.getHost()} Original URL: ` + url);
-    sdk.console.log(`${req.getHost()} Downgraded URL: ` + downgradedUrl);
+    sdk.console.log(`${req.getHost()} Original URL: ${url}`);
+    sdk.console.log(`${req.getHost()} Downgraded URL: ${downgradedUrl}`);
 
     try {
-      // Use Caido Replay SDK to replay the original request
-      const spec = new RequestSpec(downgradedUrl);
-      spec.setBody(req.getBody() as Body);
-      for (const [key, value] of Object.entries(req.getHeaders())) {
-        if (Array.isArray(value)) {
-          spec.setHeader(key, value.join(', ')); // or another suitable delimiter
-        } else {
-          spec.setHeader(key, value);
+      // 원래 요청과 다운그레이드된 요청 각각 전송
+      const downgradedResponse = await this.sendRequest(sdk, req, downgradedUrl, downgradedQuery);
+      const originalResponse = await this.sendRequest(sdk, req, url, req.getQuery());
+
+      if (downgradedResponse && originalResponse) {
+        const originalCode = originalResponse.getCode();
+        const downgradedCode = downgradedResponse.getCode();
+
+        const originalLoc = originalResponse.getHeader("location") || "";
+        const downgradedLoc = downgradedResponse.getHeader("location") || "";
+
+        sdk.console.log(`${req.getHost()} Original Status: ${originalCode}`);
+        sdk.console.log(`${req.getHost()} Downgraded Status: ${downgradedCode}`);
+        sdk.console.log(`${req.getHost()} Original Location: ${originalLoc}`);
+        sdk.console.log(`${req.getHost()} Downgraded Location: ${downgradedLoc}`);
+
+        // 두 응답 모두 리디렉션이면서 code= 파라미터 포함 시 취약점 리포트 생성
+        const bothRedirect = [301, 302].includes(originalCode) && [301, 302].includes(downgradedCode);
+        const bothContainCode = originalLoc.includes("code=") && downgradedLoc.includes("code=");
+
+        if (bothRedirect && bothContainCode) {
+          const title = isOpenID
+            ? "[CRITICAL] OpenID Flow PKCE Downgrade Vulnerability"
+            : "[CRITICAL] OAuth2 Flow PKCE Downgrade Vulnerability";
+          const reference = isOpenID
+            ? "https://openid.net/specs/openid-igov-oauth2-1_0-02.html#rfc.section.3.1.7"
+            : "https://datatracker.ietf.org/doc/html/rfc7636";
+
+          await sdk.findings.create({
+            title,
+            description: `PKCE downgrade vulnerability detected!\n\nOriginal URL: ${url}\nDowngraded URL: ${downgradedUrl}\n\nBoth requests returned authorization codes, indicating the server accepts requests without PKCE protection.\n\nReference: ${reference}`,
+            request: req,
+            reporter: "PKCE Checker",
+          });
+
+          return true;
         }
       }
-      spec.setHost(req.getHost());
-      spec.setMethod(req.getMethod());
-      spec.setPath(req.getPath());
-      spec.setQuery(downgradedQuery);
-      spec.setTls(req.getTls());
-      spec.setPort(req.getPort());
-
-      let sendDowngradedRequest = await sdk.requests.send(spec);
-
-      if (sendDowngradedRequest.response) {
-        let domain = spec.getHost();
-        let port = spec.getPort();
-        let path = spec.getPath();
-        let query = spec.getQuery();
-        let id = sendDowngradedRequest.response.getId();
-        let code = sendDowngradedRequest.response.getCode();
-        sdk.console.log(`REQ ${id}: ${domain}:${port}${path}${query} received a status code of ${code}`);
-      }
-
-      if (sendDowngradedRequest.response?.getCode() === 302) {
-        await sdk.findings.create({
-          title: isOpenID
-            ? "[CRITICAL] OpenID Flow PKCE Downgrade Vulnerability"
-            : "[CRITICAL] OAuth2 Flow PKCE Downgrade Vulnerability",
-          description: `The request to ${url} is vulnerable to a PKCE downgrade attack. This may indicate a configuration error.`,
-          request: req,
-          reporter: "PKCE Checker",
-        });
-      }
-
-/*
-      sdk.console.log(`${req.getHost()} Original Status: ` + resOriginal.status);
-      sdk.console.log(`${req.getHost()} Downgraded Status: ` + resDowngraded.status);
-
-      sdk.console.log(`${req.getHost()} Original Headers: ` + JSON.stringify(resOriginal.headers));
-      sdk.console.log(`${req.getHost()} Downgraded Headers: ` + JSON.stringify(resDowngraded.headers));
-
-      // Caido Dev Docs 기준으로, 리다이렉트된 URL은 Response 객체의 url 속성에 저장되어 있음
-      const locationOriginal = resOriginal.url ?? "";
-      const locationDowngraded = resDowngraded.url ?? "";
-
-      sdk.console.log(`${req.getHost()} Original Location: ` + locationOriginal);
-      sdk.console.log(`${req.getHost()} Downgraded Location: ` + locationDowngraded);
-
-      const statusEqual = resOriginal.status === resDowngraded.status;
-      const codeInRedirects = locationOriginal.includes("code=") && locationDowngraded.includes("code=");
-
-      if (statusEqual && codeInRedirects) {
-        const title = isOpenID
-          ? "[CRITICAL] OpenID Flow PKCE Downgraded to Plaintext"
-          : "[CRITICAL] OAuth2 Flow PKCE Downgraded to Plaintext";
-        const reference = isOpenID
-          ? "https://openid.net/specs/openid-igov-oauth2-1_0-02.html#rfc.section.3.1.7"
-          : "https://datatracker.ietf.org/doc/html/rfc7636";
-
-        await sdk.findings.create({
-          title,
-          description: `PKCE downgrade detected for ${url}.\n\nDowngraded URL: ${downgradedUrl}\n\nRedirect contained code=.\n\nReference: ${reference}`,
-          request: req,
-          reporter: "",
-        });
-
-        return true;
-      }*/
     } catch (err) {
       sdk.console.error(`PKCE downgrade check failed for ${url}: ${String(err)}`);
     }
@@ -141,4 +97,41 @@ export class PKCECheck {
     sdk.console.log("[PKCEDowngradeCheck] No PKCE downgrade detected.");
     return false;
   }
+
+  // 요청 전송 도우미 함수
+  private async sendRequest(sdk: SDK, req: Request, url: string, query: string) {
+    const spec = new RequestSpec(url);
+    spec.setMethod(req.getMethod());
+    spec.setPath(req.getPath());
+    spec.setQuery(query);
+    spec.setBody(req.getBody() as Body);
+    spec.setHost(req.getHost());
+    spec.setPort(req.getPort());
+    spec.setTls(req.getTls());
+
+    for (const [key, value] of Object.entries(req.getHeaders())) {
+      spec.setHeader(key, Array.isArray(value) ? value.join(', ') : value);
+    }
+
+    const result = await sdk.requests.send(spec);
+    return result.response ?? null;
+  }
+
+  // 경고 리포트 생성 함수
+  private async reportFinding(
+    sdk: SDK,
+    req: Request,
+    url: string,
+    isOpenID: boolean,
+    title: string,
+    message: string
+  ) {
+    const fullTitle = isOpenID ? `[WARN] OpenID Flow ${title}` : `[WARN] OAuth2 Flow ${title}`;
+    await sdk.findings.create({
+      title: fullTitle,
+      description: `${message} (${url})`,
+      request: req,
+      reporter: "PKCE Checker",
+    });
+  }
 }
diff --git a/packages/backend/src/controller/accessTokenDetector.ts b/packages/backend/src/controller/accessTokenDetector.ts
index 6e95120..c0570d0 100644
--- a/packages/backend/src/controller/accessTokenDetector.ts
+++ b/packages/backend/src/controller/accessTokenDetector.ts
@@ -19,7 +19,7 @@ export class AccessTokenLeakController {
         title: result.title,
         description: result.description,
         request,
-        reporter: "",
+        reporter: "AccessTokenLeak",
       });
     }
   }
@@ -31,7 +31,7 @@ export class AccessTokenLeakController {
         title: result.title,
         description: result.description,
         request,
-        reporter: "",
+        reporter: "AccessTokenLeak",
       });
     }
   }
@@ -132,34 +132,53 @@ export class AccessTokenLeakController {
    * @param text - 검사할 텍스트
    * @returns 토큰 값이 있으면 해당 값, 없으면 null
    */
-private extractTokenFromText(text: string): string | null {
+  private extractTokenFromText(text: string): string | null {
      // 토큰 관련 키워드 리스트
     const tokenKeys = [
-        'access_token',
-        'accesstoken',
-        'Access-Token',
-        'Refresh_Token',
-        'Refresh-Token',
-        'RefreshToken',
-        'Secret_Token',
-        'Secret-Token',
-        'SecretToken',
-        'SSO_Auth',
-        'SSO-Auth',
-        'SSOAuth',
-        'auth_token',
-        'session_token'
-     ];
+      'access_token',
+      'accesstoken',
+      'Access-Token',
+      'Refresh_Token',
+      'Refresh-Token',
+      'RefreshToken',
+      'Secret_Token',
+      'Secret-Token',
+      'SecretToken',
+      'SSO_Auth',
+      'SSO-Auth',
+      'SSOAuth',
+      'auth_token',
+      'session_token'
+    ];
 
-  // 정규표현식 패턴 리스트 생성
+    const tokenTypeKeys = [
+      'token_type',
+      'tokenType'
+    ];
+
+     // 정규표현식 토큰 타입 유무 패턴 리스트 생성
+    const tokenTypeRegexes: RegExp[] = [];
+    for (const key of tokenTypeKeys) {
+      // JSON 형식: "token_type": "Bearer"
+      tokenTypeRegexes.push(new RegExp(`"${key}"\\s*:\\s*"bearer"`, 'i'));
+      // 일반 key=value 형식: token_type=Bearer
+      tokenTypeRegexes.push(new RegExp(`${key}[=:]\\s*bearer`, 'i'));
+      // 공백 있는 형식: token_type : Bearer
+      tokenTypeRegexes.push(new RegExp(`${key}\\s*:\\s*bearer`, 'i'));
+    }
+
+    // token_type=bearer 형태 중 하나라도 포함되는지 확인
+    const hasTokenTypeBearer = tokenTypeRegexes.some(rx => rx.test(text));
+
+    // 정규표현식 토큰 유무 패턴 리스트 생성
     const tokenPatterns: RegExp[] = [];
 
     for (const key of tokenKeys) {
-        // 1. key=token 또는 key: token
-        tokenPatterns.push(new RegExp(`${key}[=:]\\s*([a-zA-Z0-9\\-._~+/]+=*)`, 'i'));
+      // 1. key=token 또는 key: token
+      tokenPatterns.push(new RegExp(`${key}[=:]\\s*([a-zA-Z0-9\\-._~+/]+=*)`, 'i'));
 
-        // 2. JSON 형태의 "key": "token"
-        tokenPatterns.push(new RegExp(`"${key}"\\s*:\\s*"([^"]+)"`, 'i'));
+      // 2. JSON 형태의 "key": "token"
+      tokenPatterns.push(new RegExp(`"${key}"\\s*:\\s*"([^"]+)"`, 'i'));
     }
 
     // 3. Authorization: Bearer <token> 형태
@@ -167,12 +186,14 @@ private extractTokenFromText(text: string): string | null {
 
     // 모든 패턴에 대해 검사
     for (const pattern of tokenPatterns) {
-        const match = pattern.exec(text);
-        if (match && match[1]) {
-        return match[1];
+      const match = pattern.exec(text);
+      if (match && match[1]) {
+        if(hasTokenTypeBearer){
+          return match[1];
         }
+      }
     }
 
     return null;
-    }
+  }
 }
\ No newline at end of file
diff --git a/packages/backend/src/controller/csrfCheck.ts b/packages/backend/src/controller/csrfCheck.ts
index f5018d5..8a6f723 100644
--- a/packages/backend/src/controller/csrfCheck.ts
+++ b/packages/backend/src/controller/csrfCheck.ts
@@ -5,15 +5,24 @@ import { HttpUtils } from "../utils/http";
 const httpUtils = new HttpUtils();
 
 export class CsrfCheck {
+  private nonceParam = [
+    "state",
+    "nonce",
+    "as",
+    "frame_id",
+    "csrf_token",
+    "csrf",
+  ];
+
   private isTargetUri(uri: string): boolean {
     if (
-      uri.includes("client_id=") &&
-      (uri.includes("response_type=") ||
-        uri.includes("grant_type=") ||
-        uri.includes("redirect_uri=") ||
-        uri.includes("scope=") ||
-        uri.includes("state=") ||
-        uri.includes("nonce="))
+      httpUtils.getQueryParamFromURI(uri, "client_id") !== null &&
+      (httpUtils.getQueryParamFromURI(uri, "response_type") !== null ||
+        httpUtils.getQueryParamFromURI(uri, "grant_type") !== null ||
+        httpUtils.getQueryParamFromURI(uri, "redirect_uri") !== null ||
+        httpUtils.getQueryParamFromURI(uri, "scope") !== null ||
+        httpUtils.getQueryParamFromURI(uri, "state") !== null ||
+        httpUtils.getQueryParamFromURI(uri, "nonce") !== null)
     ) {
       return true;
     }
@@ -43,105 +52,178 @@ export class CsrfCheck {
     return false;
   }
 
-  private isStateInQuery(request: Request): boolean {
-    const query = request.getQuery();
-    const stateValue =
-      httpUtils.getQueryParam(query || "", "state") ||
-      httpUtils.getQueryParam(query || "", "nonce");
-    if (!stateValue) {
-      return false;
+  private isNonceInQuery(request: Request): boolean {
+    const query = request.getQuery() || "";
+
+    for (const param of this.nonceParam) {
+      if (httpUtils.getQueryParam(query, param) !== null) {
+        return true; // Nonce parameter is present in the query
+      }
     }
-    return true;
+
+    return false; // No nonce parameter found in the query
   }
 
-  private checkStateAtResponseLocationHeader(
+  private getNonceParamName(url: string): string | null {
+    for (const param of this.nonceParam) {
+      if (httpUtils.getQueryParamFromURI(url, param) !== null) {
+        return param; // Return the first matching nonce parameter
+      }
+    }
+
+    return null; // No nonce parameter found
+  }
+
+  private checkNonceAtResponseLocationHeader(
     request: Request,
     response: Response
   ): string[] | 0 {
+    const nonceParamName = this.getNonceParamName(request.getUrl() || "");
+
     if (
-      !(
-        this.isOauthUri(request) &&
-        this.isStateInQuery(request) &&
-        this.isOauthRedirectResponse(response)
-      )
+      !this.isOauthUri(request) ||
+      !this.isNonceInQuery(request) ||
+      !this.isOauthRedirectResponse(response) ||
+      !nonceParamName
     ) {
       return 0; // Not a target, no CSRF risk
     }
 
-    // 요청에서 보낸 state 추출
+    // 요청에서 보낸 Nonce 추출
     const query = request.getQuery() || "";
-    const originalState =
-      httpUtils.getQueryParam(query, "state") ||
-      httpUtils.getQueryParam(query || "", "nonce");
+    const originalNonce = httpUtils.getQueryParam(query, nonceParamName);
 
     // 리다이렉트 URL에서 쿼리 부분만 추출
-    const locationHeader = httpUtils.getHeaderValue(
-      response.getHeaders(),
-      "location"
-    );
-    const responseState =
-      httpUtils.getQueryParamFromURI(locationHeader || "", "state") ||
-      httpUtils.getQueryParamFromURI(locationHeader || "", "nonce");
+    const locationHeader =
+      httpUtils.getHeaderValue(response.getHeaders(), "location") || "";
 
-    // state가 없거나, 요청값과 다르면 CSRF 위험
-    if (!responseState) {
+    const responseNonce = httpUtils.getQueryParamFromURI(
+      locationHeader || "",
+      nonceParamName
+    );
+
+    // Nonce가 없거나, 요청값과 다르면 CSRF 위험
+    if (!responseNonce) {
       // missing state
-      return ["state parameter is missing in the response location header"];
+      return ["Nonce parameter is missing in the response location header"];
     }
-    if (originalState !== responseState) {
+    if (originalNonce !== responseNonce) {
       // mismatch
-      return ["state parameter mismatch between request and response"];
+      return ["Nonce parameter mismatch between request and response"];
     }
 
     return 0; // no CSRF risk detected
   }
 
-  // private async checkStateReuse(
-  //   request: Request,
-  //   originResponse: Response
-  // ): Promise<string[] | 0> {
-  //   // uri에 oauth 관련 파라미터가 없지만, 응답이 oauth 리다이렉트 응답인지 확인
-  //   // 즉, 처음으로 state를 발급한 요청인지 확인
-  //   if (
-  //     !(
-  //       !this.isOauthUri(request) &&
-  //       this.isOauthRedirectResponse(originResponse)
-  //     )
-  //   ) {
-  //     return 0; // Not a target, no CSRF risk
-  //   }
+  private async checkNonceReuse(
+    sdk: SDK<DefineAPI<{}>, {}>,
+    request: Request,
+    originResponse: Response
+  ): Promise<string[] | 0> {
+    // uri에 oauth 관련 파라미터가 없지만, 응답이 oauth 리다이렉트 응답인지 확인
+    // 즉, 처음으로 Nonce를 발급한 요청인지 확인
+    if (
+      this.isOauthUri(request) ||
+      !this.isOauthRedirectResponse(originResponse)
+    ) {
+      return 0; // Not a target, no CSRF risk
+    }
 
-  //   const originResponseLocationHeader = httpUtils.getHeaderValue(
-  //     originResponse.getHeaders(),
-  //     "location"
-  //   );
-  //   const originState = httpUtils.getQueryParamFromURI(
-  //     originResponseLocationHeader || "",
-  //     "state"
-  //   );
+    // 기존 응답의 location 헤더의 url에서 Nonce 파라미터 이름, nonce 파라미터 값, 쿼리 추출
+    const originResponseLocationHeader =
+      httpUtils.getHeaderValue(originResponse.getHeaders(), "location") || "";
+    const nonceParamName =
+      this.getNonceParamName(originResponseLocationHeader || "") || "state";
+    const originLocationQuery =
+      httpUtils.getQueryFromURI(originResponseLocationHeader || "") || "";
+    const originLocationNonce = httpUtils.getQueryParam(
+      originLocationQuery,
+      nonceParamName
+    );
 
-  //   const requestHeaders = request.getHeaders();
-  //   const noCookieHeaders = httpUtils.removeHeaders(requestHeaders, ["cookie"]);
-  //   const newResponse = await httpUtils.resend(request, {
-  //     headers: noCookieHeaders,
-  //   });
-  //   const newLocationHeader = httpUtils.getHeaderValue(
-  //     newResponse.getHeaders(),
-  //     "location"
-  //   );
-  //   const newState = httpUtils.getQueryParamFromURI(
-  //     newLocationHeader || "",
-  //     "state"
-  //   );
+    // 쿠키가 없는 헤더로 새로운 nonce를 발급받기 위해 요청
+    const noCookieHeaders = httpUtils.removeHeaders(request.getHeaders(), [
+      "cookie",
+    ]);
+    const noCookieResponse = await httpUtils.resend(sdk, request, {
+      headers: noCookieHeaders,
+    });
+    if (!noCookieResponse || noCookieResponse?.getCode() >= 400) {
+      return 0;
+    }
 
-  //   if (originState === newState) {
-  //     return [
-  //       "State parameter reused in the response location header, indicating a potential CSRF risk",
-  //     ];
-  //   }
+    // 쿠키가 없는 응답의 location 헤더 추출 및 Nonce 추출
+    const noCookieLocationHeader = httpUtils.getHeaderValue(
+      noCookieResponse?.getHeaders() || {},
+      "location"
+    );
+    const newNonce =
+      httpUtils.getQueryParamFromURI(
+        noCookieLocationHeader || "",
+        nonceParamName
+      ) || "";
 
-  //   return 0; // no CSRF risk detected
-  // }
+    if (originLocationNonce === newNonce) {
+      return [
+        "State parameter reused in the response location header, indicating a potential CSRF risk",
+      ];
+    }
+
+    // 기존 쿠키와 함께 새로운 Nonce로 요청
+    const newQuery = httpUtils.setQueryParam(
+      originLocationQuery,
+      nonceParamName,
+      newNonce
+    );
+
+    // 기존 location 헤더의 uri 요청과 location 헤더에서 nonce값만 새로 발급한 값으로 바꾸어 요청한 결과를 비교
+    const res1 = await httpUtils.customFetch(
+      sdk,
+      originResponseLocationHeader,
+      "GET",
+      originLocationQuery,
+      request.getHeaders()
+    );
+
+    const res2 = await httpUtils.customFetch(
+      sdk,
+      originResponseLocationHeader,
+      "GET",
+      newQuery,
+      request.getHeaders()
+    );
+
+    if (
+      !res1 ||
+      !res2 ||
+      res1.getCode() >= 400 ||
+      res2.getCode() >= 400 ||
+      res1.getCode() !== res2.getCode()
+    ) {
+      return 0;
+    }
+
+    if (
+      res1.getCode() === res2.getCode() &&
+      300 <= res1.getCode() &&
+      res1.getCode() < 400
+    ) {
+      const res1LocationHeader =
+        httpUtils.getHeaderValue(res1.getHeaders(), "location") || "";
+      const res2LocationHeader =
+        httpUtils.getHeaderValue(res2.getHeaders(), "location") || "";
+      const res1ReirectPath = httpUtils.getPathFromURI(res1LocationHeader);
+      const res2ReirectPath = httpUtils.getPathFromURI(res2LocationHeader);
+
+      if (res1ReirectPath === res2ReirectPath) {
+        return [
+          "When nonce parameter reused in the response location header, it might not be verified. Indicating a potential CSRF risk",
+        ];
+      }
+    }
+
+    return 0; // no CSRF risk detected
+  }
 
   async checker(
     sdk: SDK<DefineAPI<{}>, {}>,
@@ -151,30 +233,45 @@ export class CsrfCheck {
     let result = ``;
 
     // 쿼리에 state 파라미터가 없으면 CSRF 위험
-    if (this.isOauthUri(request) && !this.isStateInQuery(request)) {
-      result += "CSRF risk: missing state parameter"; // CSRF risk: missing state parameter
+    try {
+      if (this.isOauthUri(request) && !this.isNonceInQuery(request)) {
+        result += "CSRF risk: missing state parameter"; // CSRF risk: missing state parameter
+      }
+    } catch (error) {
+      sdk.console.error(`Error checking state in query: ${error}`);
     }
 
     // location 헤더에 state 파라미터가 없거나, 요청에서 보낸 state와 다르면 CSRF 위험
-    const stateAtResponseLocationHeaderCheck =
-      this.checkStateAtResponseLocationHeader(request, response);
-    if (stateAtResponseLocationHeaderCheck !== 0) {
-      result += `, ${stateAtResponseLocationHeaderCheck.join(", ")}`;
+    try {
+      const stateAtResponseLocationHeaderCheck =
+        this.checkNonceAtResponseLocationHeader(request, response);
+      if (stateAtResponseLocationHeaderCheck !== 0) {
+        result += `, ${stateAtResponseLocationHeaderCheck.join(", ")}`;
+      }
+    } catch (error) {
+      sdk.console.error(
+        `Error checking state in response location header: ${error}`
+      );
     }
 
-    // // 처음으로 state를 발급한 요청에서 state 파라미터를 바꿔서 보내기
-    // const reusedStateCheck = await this.checkStateReuse(request, response);
-    // if (reusedStateCheck !== 0) {
-    //   result += `, ${reusedStateCheck.join(", ")}`;
-    // }
+    // 처음으로 state를 발급한 요청에서 state 파라미터를 바꿔서 보내기
+    const reusedStateCheck = await this.checkNonceReuse(sdk, request, response);
+    if (reusedStateCheck !== 0) {
+      result += `, ${reusedStateCheck.join(", ")}`;
+    }
 
-    if (result) {
-      await sdk.findings.create({
-        title: "csrf vuln",
-        description: `SSO-related parameters detected in response:\n\n${request.getMethod()} ${request.getUrl()} : ${result}`,
-        request,
-        reporter: "csrf reporter",
-      });
+    try {
+      result.replace(/^\s*,\s*|\s*$/, ""); // Remove leading/trailing commas
+      if (result) {
+        await sdk.findings.create({
+          title: "csrf vuln",
+          description: `SSO-related parameters detected in response:\n\n${request.getMethod()} ${request.getUrl()} : ${result}`,
+          request,
+          reporter: "csrf reporter",
+        });
+      }
+    } catch (error) {
+      sdk.console.error(`Error creating finding: ${error}`);
     }
   }
 }
diff --git a/packages/backend/src/controller/redirect_uriBypass.ts b/packages/backend/src/controller/redirect_uriBypass.ts
new file mode 100644
index 0000000..ce521cb
--- /dev/null
+++ b/packages/backend/src/controller/redirect_uriBypass.ts
@@ -0,0 +1,59 @@
+import type { Request, Response } from "caido:utils";
+import type { SDK } from "caido:plugin";
+
+export class RedirectBypassController {
+  // redirect_uri를 확인하는 함수
+  isRedirectUri(req: Request): { detected: boolean; redirectUri?: string } {
+    // ? 뒤에 오는 파라미터 모두 가져오고, 정규표현식으로 redirect_uri= 이후 주소만 뽑음(없으면 null)  
+    const query = req.getQuery();
+    const redirectUriMatch = query.match(/redirect_uri=([^&]+)/i);
+
+    // redirectUriMatch[1]은 ()로 감싼 부분 
+    // redirect_uri 파라미터가 없거나 있어도 주소가 문자열이 아니면 false 
+    if (!redirectUriMatch || typeof redirectUriMatch[1] !== "string") {
+      return { detected: false };
+    }
+
+    // 인코딩된 주소를 원래대로 바꿈 (ex. https://~~)
+    const redirectUri = decodeURIComponent(redirectUriMatch[1]);
+
+    const bypassPatterns = [
+      "%ff@", "／", "%2f@", "%0a@", "%0d@", "\\", ".evil.com", "@", "%2f..%2f",
+    ];
+    
+    // 위 패턴에 일치하는 게 있으면 true랑 redirectUri 반환 (false일 땐 undefined)
+    const detected = bypassPatterns.some(pattern => redirectUri.includes(pattern));
+    return { detected, redirectUri: detected ? redirectUri : undefined };
+  }
+
+  // 응답에 인가 코드가 포함되어 있는지 확인하는 함수 
+  isCodeIssued(res: Response): boolean {
+    const location = res.getHeader("Location") || "";
+    return location.includes("code=");
+  }
+
+  // 위의 두 함수 모두 만족하면 true, 문제의 주소를 반환하는 함수 
+  test(req: Request, res: Response): { detected: boolean; redirectUri?: string } {
+    const redirectCheck = this.isRedirectUri(req);
+    const codeIssued = this.isCodeIssued(res);
+    
+    if (redirectCheck.detected && codeIssued) {
+      return { detected: true, redirectUri: redirectCheck.redirectUri };
+    }
+    
+    return { detected: false };
+  }
+
+  // 탐지된 결과 저장하는 함수 
+  async testAsync(sdk: SDK, req: Request, res: Response): Promise<void> {
+    const result = this.test(req, res);
+    if (result.detected) {
+      await sdk.findings.create({
+        title: "Redirect URI Bypass Detected",
+        description: `redirect_uri 우회 발견\nRedirect URI: ${result.redirectUri}`,
+        request: req,
+        reporter: "gyu",
+      });
+    }
+  }
+}
diff --git a/packages/backend/src/index.ts b/packages/backend/src/index.ts
index 0534c99..c745398 100644
--- a/packages/backend/src/index.ts
+++ b/packages/backend/src/index.ts
@@ -7,24 +7,23 @@ import { PKCECheck } from "./controller/PKCECheck";
 import { AccessTokenLeakController } from "./controller/accessTokenDetector";
 import { ScopeDetection } from "./controller/scopeDetection";
 import { NonceCheckController } from "./controller/nonceCheck";
+import { RedirectBypassController } from "./controller/redirect_uriBypass";
 
 export type API = DefineAPI<{}>;
 
 const csrfCheck = new CsrfCheck();
-// const implicitGrantController = new ImplicitGrantController();
-// const authZCodeGrantController = new AuthZCodeGrantController();
 const pkceCheckController = new PKCECheck();
 const tokenCheck = new AccessTokenLeakController();
 const ScopeDetectionController = new ScopeDetection();
-
+const redirectBypassController = new RedirectBypassController();
 
 export function init(sdk: SDK<API>) {
   sdk.events.onInterceptResponse(async (sdk, req: Request, res: Response) => {
     await csrfCheck.checker(sdk, req, res);
-    await pkceCheckController.test(sdk, req);
-    await tokenCheck.testReq(sdk, req);
+    //await pkceCheckController.test(sdk, req);
     await tokenCheck.testResp(sdk, res, req);
     await ScopeDetectionController.scan(sdk, req.getUrl());
+    await redirectBypassController.testAsync(sdk, req, res);
 
     // isOidcFlow는 비동기 메서드로 변경
     if (await NonceCheckController.isOidcFlow(req, res)) {
@@ -37,6 +36,10 @@ export function init(sdk: SDK<API>) {
     }
   });
 
+  sdk.events.onInterceptRequest(async (sdk, req: Request) => {
+    await tokenCheck.testReq(sdk, req);
+    await pkceCheckController.test(sdk, req);
+  });
   /*
   sdk.events.onInterceptRequest(async (sdk, req: Request) => {
     const result =
diff --git a/packages/backend/src/utils/http.ts b/packages/backend/src/utils/http.ts
index 56a6fe1..01e2cfc 100644
--- a/packages/backend/src/utils/http.ts
+++ b/packages/backend/src/utils/http.ts
@@ -1,3 +1,6 @@
+import type { SDK } from "caido:plugin";
+import { Body, RequestSpec, type Request, type Response } from "caido:utils";
+
 let instance: HttpUtils | null = null;
 export class HttpUtils {
   /**
@@ -11,6 +14,14 @@ export class HttpUtils {
     return instance;
   }
 
+  encodeAndLower(value: string): string {
+    try {
+      return encodeURIComponent(value).toLowerCase();
+    } catch {
+      return value.toLowerCase();
+    }
+  }
+
   /**
    * URI 디코딩 후 소문자로 변환하는 헬퍼 함수
    * @param value - 디코딩하고 소문자로 변환할 문자열
@@ -47,12 +58,35 @@ export class HttpUtils {
     return result;
   }
 
-  getQueryParamFromURI(uri: string, key: string): string | null {
+  getPathFromURI(uri: string): string | null {
     uri = uri.toLowerCase();
-    key = key.toLowerCase();
     try {
       const urlObj = new URL(uri);
-      return urlObj.searchParams.get(key);
+      const path = urlObj.pathname;
+      return path ? decodeURIComponent(path) : null; // 경로가 없으면 null 반환
+    } catch (e) {
+      return null; // URL 파싱 실패 시 null 반환
+    }
+  }
+
+  getQueryFromURI(uri: string): string | null {
+    uri = uri.toLowerCase();
+    try {
+      const urlObj = new URL(uri);
+      const query = urlObj.search;
+      return query ? decodeURIComponent(query.slice(1)) : null; // 쿼리 문자열에서 ? 제거
+    } catch (e) {
+      return null; // URL 파싱 실패 시 null 반환
+    }
+  }
+
+  getQueryParamFromURI(uri: string, key: string): string | null {
+    uri = uri.toLowerCase();
+    key = this.decodeAndLower(key);
+    try {
+      const urlObj = new URL(uri);
+      const param = urlObj.searchParams.get(key);
+      return param ? decodeURIComponent(param) : null;
     } catch (e) {
       return null;
     }
@@ -67,10 +101,11 @@ export class HttpUtils {
    */
   getQueryParam(query: string, key: string): string | null {
     query = query.toLowerCase();
-    key = key.toLowerCase();
+    key = this.decodeAndLower(key);
 
     const params = new URLSearchParams(query);
-    return params.get(key);
+    const targetParam = params.get(key);
+    return targetParam ? decodeURIComponent(targetParam) : null;
   }
 
   /**
@@ -83,11 +118,11 @@ export class HttpUtils {
    */
   setQueryParam(query: string, key: string, value: string): string {
     query = query.toLowerCase();
-    key = key.toLowerCase();
-    value = value.toLowerCase();
+    key = this.decodeAndLower(key);
+    value = this.decodeAndLower(value);
 
     const params = new URLSearchParams(query);
-    params.set(key, value);
+    params.set(key, this.encodeAndLower(value));
     return params.toString();
   }
 
@@ -100,7 +135,7 @@ export class HttpUtils {
    */
   removeQueryParam(query: string, key: string): string {
     query = query.toLowerCase();
-    key = key.toLowerCase();
+    key = this.decodeAndLower(key);
 
     const params = new URLSearchParams(query);
     params.delete(key);
@@ -109,6 +144,7 @@ export class HttpUtils {
 
   // Headers
   /**
+   * !! 만약 request.getHeader(`${key}`)을 사용할 수 있다면 이 함수를 사용하지 마세요.
    * 주어진 헤더 맵에서 name에 해당하는 첫 번째 헤더 값을 반환합니다.
    * @param headers     - Response.getHeaders() 가 반환하는 객체
    * @param name        - 꺼내고 싶은 헤더 이름 (예: "location", "Content-Type")
@@ -207,4 +243,89 @@ export class HttpUtils {
     }
     return filtered;
   }
+
+  async resend(
+    sdk: SDK,
+    request: Request,
+    options?: {
+      headers?: Record<string, string | string[]>;
+      body?: Body;
+      method?: string;
+      query?: string;
+    }
+  ): Promise<Response | null> {
+    try {
+      const spec = new RequestSpec(request.getUrl());
+      spec.setMethod(options?.method || request.getMethod() || "GET");
+      if (options?.query) {
+        spec.setQuery(options.query);
+      } else {
+        spec.setQuery(request.getQuery() || "");
+      }
+
+      const originBody = request.getBody();
+      if (options?.body) {
+        spec.setBody(options.body);
+      } else if (originBody) {
+        spec.setBody(originBody);
+      }
+
+      const headers = request.getHeaders();
+      if (options?.headers) {
+        // 기존 헤더에서 options.headers로 덮어쓰기
+        const newHeaders = this.lowerCaseAllHeaders({
+          ...headers,
+          ...options.headers,
+        });
+        for (const [key, value] of Object.entries(newHeaders)) {
+          spec.setHeader(key, Array.isArray(value) ? value.join(", ") : value);
+        }
+      } else {
+        // 기존 헤더 그대로 사용
+        for (const [key, value] of Object.entries(headers)) {
+          spec.setHeader(key, Array.isArray(value) ? value.join(", ") : value);
+        }
+      }
+
+      const result = await sdk.requests.send(spec);
+      return result.response ?? null;
+    } catch (error) {
+      sdk.console.error(
+        `Error resending request to ${request.getUrl()}: ${String(error)}`
+      );
+      return null;
+    }
+  }
+
+  async customFetch(
+    sdk: SDK,
+    url: string,
+    method?: string,
+    query?: string,
+    headers?: Record<string, string | string[]>,
+    body?: Body
+  ): Promise<Response | null> {
+    try {
+      const spec = new RequestSpec(url);
+      spec.setMethod(method || "GET");
+      if (query) {
+        spec.setQuery(query);
+      }
+      if (body) {
+        spec.setBody(body);
+      }
+
+      for (const [key, value] of Object.entries(headers || {})) {
+        spec.setHeader(key, Array.isArray(value) ? value.join(", ") : value);
+      }
+
+      const result = await sdk.requests.send(spec);
+      return result.response ?? null;
+    } catch {
+      sdk.console.error(
+        `Error during custom fetch to ${url}: ${String(error)}`
+      );
+      return null;
+    }
+  }
 }
diff --git a/playground/csrf/index.js b/playground/csrf/index.js
index 5c7a733..01c2bba 100644
--- a/playground/csrf/index.js
+++ b/playground/csrf/index.js
@@ -1,5 +1,6 @@
 // app.js
 const express = require("express");
+const crypto = require("crypto");
 const app = express();
 const port = 8000;
 
@@ -43,8 +44,6 @@ app.get("/authorize/mismatch-state", (req, res) => {
   );
   const code = "authcode-67890";
 
-  console.log(`[VULN] original state from client:`, originalState);
-
   // 클라이언트 state와 다르게 'wrong-state'를 삽입
   const wrongState = "wrong-state";
   const location = `${redirectUri}?code=${code}&state=${wrongState}&client_id=${clientId}`;
@@ -52,6 +51,24 @@ app.get("/authorize/mismatch-state", (req, res) => {
   res.status(302).send(`Redirecting to ${location}`);
 });
 
+/**
+ * 3) 랜덤 state를 생성하여 리다이렉트를 발생시키는 테스트용 엔드포인트
+ *    - /authorize/reuse-state-test 로 접근할 때마다 새로운 16진수 state를 생성
+ *    - 최초 요청에 OAuth 파라미터가 없으므로 isOauthUri(request) == false
+ *    - 응답에 Location 헤더로 '...?state=<랜덤값>' 을 포함
+ *    -> Caido 플러그인의 checkNonceReuse 로직에서 새로운 state가 발급되었는지,
+ *       재사용되었는지를 검증할 수 있음
+ *    - 더하여 callback uri에서 해당 nonce의 유효성을 판단하지 않고 응답 시에 vuln
+ */
+app.get("/authorize/reuse-state-test", (req, res) => {
+  const state = crypto.randomBytes(16).toString("hex");
+
+  // 고정된 콜백 URI로 리다이렉트 (OAuth 파라미터는 여기서만 주입)
+  const location = `http://localhost:${port}/callback?state=${state}&client_id=123`;
+  res.set("Location", location);
+  res.status(302).send(`Redirecting to ${location}`);
+});
+
 app.listen(port, () => {
   console.log(
     `Vulnerable OAuth test server listening at http://localhost:${port}`
@@ -62,4 +79,7 @@ app.listen(port, () => {
   console.log(
     `2) Mismatch-State: http://localhost:${port}/authorize/mismatch-state?client_id=abc&state=xyz&redirect_uri=http://localhost:${port}/callback`
   );
+  console.log(
+    `3) Reuse-State-Test:    http://localhost:${port}/authorize/reuse-state-test`
+  );
 });